Cornerback Aaron Ross, who signed a three-year $15.3 million free agent contract with the Jaguars last spring, is now a nickel back for the team.

Rashean Mathis replaced Ross at left corner Sunday against the Colts.

Mathis didn't start the first two games because the Jaguars were bringing him along slowly as he recovered from his torn ACL,but they feel he is ready to start so he replaced Ross in the starting lineup.

The right corner job belongs to Derek Cox, who started against the Colts Sunday. He was active for the Colts’ game for the first time since pulling a hamstring on the fourth play of the preseason opener.

So after starting Ross and William Middleton as the corner spots last week, they have Mathis and Cox and hope that will help their pass defense. And Ross is the nickel back and when they had six defensive backs on the Colts' first third down play, safety Chris Prosinski was the sixth back. On the Colts second third down play, they used a nickel defense with Ross as the nickel. But the dime defense gave up a 40-yard touchdown pass by Andrew Luck.

In another development, the Jaguars gave undrafted free agent rookie Mike Brewster a shot at starting at left guard for ailing Eben Britton. Last week, they started Herb Taylor for Britton even though he had been with the team less than a week. Brewster was bypassed in the draft even though he ended his career at Ohio State with 49 straight starts. He was a center for the Buckeyes.

The Jaguars also will keep defensive end Austen Lane on the inactive list for another week even though he said he was ready to play. That should mean Jeremy Mincey will again get a lot of snaps because they have only three ends active – Mincey, Andre Branch and Aaron Morgan although they can switch a tackle to end at times.

With Lane still out, the only change in the inactive list from last week is that Cox is active and Jeris Pendleton will be inactive as the only healthy inactive.

The Jaguars suffered two early setbacks when fullback Greg Jones and wide receiver Laurent Robinson went out with blows to the head. Both were listed as questionable to return.